Motor

ABSTRACT

A motor includes a rotor, a stator, a first substrate, a second substrate, and an electronic component arranged at the second substrate. The stator includes a stator core, an insulator, and a coil wound around the stator core via the insulator. The insulator includes a coupling part connected to an external device. The first substrate is fixed to the insulator. The second substrate is fixed to the first substrate. The first substrate and the second substrate are spaced apart in a rotation axis direction of the rotor.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Japanese Application No.2020-182862, filed Oct. 30, 2020, the entire disclosure of which ishereby incorporated herein by reference.

Technical Field

The present invention relates to a motor.

Background Art

There is known a technique concerning a motor operating with alternatingcurrent (AC) power, and in this technique, a brushless motor includingan AC-DC converter is used in order to meet a demand for an increasedservice life and reduced noise.

CITATION LIST Patent Literature

Patent Document 1: Japanese Patent Application Laid-open No. 2001-128432

Patent Document 2: Japanese Patent Application Laid-open No. 2015-95920

Patent Document 3: Japanese Patent Application Laid-open No. H08-140325

Patent Document 4: Japanese Patent Application Laid-open No. 2019-83611

SUMMARY OF INVENTION Technical Problem

For a direct current motor including an AC-DC converter, more weightreduction and size reduction are desired.

An object of one aspect is to provide a motor capable of achievingweight reduction and noise reduction.

Solution to Problem

In one mode, a motor includes a rotor, a stator, a first substrate, asecond substrate, and an electronic component arranged at the secondsubstrate. The stator includes a stator core, an insulator, and a coilwound around the stator core via the insulator. The insulator includes acoupling part coupled to an external device. The first substrate isfixed to the insulator. The second substrate is fixed to the firstsubstrate. The first substrate and the second substrate are spaced apartin a rotation axis direction of the rotor.

With the one mode, it is possible to achieve the weight reduction andnoise reduction.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating one example of a motoraccording to a first embodiment.

FIG. 2 is a cross-sectional view illustrating one example of the motoraccording to the first embodiment.

FIG. 3 is a perspective view illustrating the motor according to thefirst embodiment, and in this view, a housing of the motor is removed.

FIG. 4 is a perspective view illustrating one example of an insulatoraccording to the first embodiment.

FIG. 5 is a bottom view illustrating one example of the motor accordingto the first embodiment.

FIG. 6 is an enlarged cross-sectional view illustrating one example ofthe motor according to the first embodiment.

FIG. 7 is a perspective view illustrating one example of a housingaccording to the first embodiment.

DESCRIPTION OF EMBODIMENTS

An example of a motor disclosed in the present application will bedescribed below in detail with reference to the drawings. Note that thedimensional relationships, the proportions, and the like betweenelements in the drawings may differ from those in reality. Among thedrawings, the dimensional relationships and proportions may notnecessarily be the same. In each of the drawings, a coordinate systemincluding at least any one of an axial direction (rotation axisdirection of a motor 1), a radial direction, or a circumferentialdirection of the motor 1, which will be described later, may beillustrated for the purpose of facilitating explanation. In addition,the rotation axis direction of the motor 1 may be simply referred to asan “axial direction” below.

FIG. 1 is a perspective view illustrating one example of a motoraccording to a first embodiment. FIG. 2 is a cross-sectional viewillustrating one example of the motor according to the first embodiment.FIG. 3 is a perspective view of the motor according to the firstembodiment. In FIG. 3, a housing of the motor is removed. FIG. 2illustrates a cross section taken along the line A-A in FIG. 1. Asillustrated in FIGS. 1 to 3, the motor 1 according to the presentembodiment includes a stator 2, a rotor 40, a first substrate 50, asecond substrate 60, a housing 70, a shaft 80, and a bearing housing 90.The stator 2 includes an insulator 10, a stator core 20, and a coil 30.

In the present embodiment, the insulator 10 is formed with an insulatingmember such as resin. The stator core 20 is configured, for example, bystacking, in the axial direction, a predetermined number of steel sheetsformed of a magnetic substance such as a silicon steel sheet. The statorcore 20 includes a teeth part 21 protruding in the radial direction, anda core back 22 extending in the circumferential direction. The coil 30is wound around the stator core 20 via the insulator 10.

The coil 30 includes, for example, a winding line such as a copper line.For example, the rotor 40 includes a magnet 41 such as a neodymiummagnet, and a yoke 42 serving as a magnetic body.

In the present embodiment, the first substrate 50 is, for example, adriver circuit configured to control operation of the motor 1. Thesecond substrate 60 receives alternating current (AC) power suppliedfrom the outside, and supplies direct current (DC) power to the motor 1.

The housing 70 is formed of metal such as steel, and accommodates thestator 2. The shaft 80 includes an end part 81 opposing to the firstsubstrate 50 in the axial direction and disposed at an upper directionside in the drawing, and an output-side end part 82 disposed at a lowerdirection side in the drawing. The shaft 80 is inserted into the bearinghousing 90.

FIG. 4 is a perspective view illustrating one example of the insulatoraccording to the first embodiment. As illustrated in FIG. 4, theinsulator 10 includes an outer circumference part 11, a connecting part12, an internal circumference part 13, and coupling parts 14. Inaddition, at an upper side in the axial direction, the insulator 10further includes a fixing part 15, a first conductive member 16, and asecond conductive member 17, as illustrated in FIG. 4.

For example, the insulator 10 is mounted at the stator core 20 fromabove in the axial direction, as illustrated in FIG. 2. Note that theinsulator 10 may be configured by, for example, being combined with alower insulator 18 mounted at the stator core 20 from below in the axialdirection, as illustrated in FIG. 2.

As illustrated in FIGS. 2 to 4, the outer circumference part 11 of theinsulator 10 opposes to the core back 22 of the stator core 20 in theaxial direction. In addition, the connecting part 12 of the insulator 10opposes to the teeth part 21 of the stator core 20 in the axialdirection. The coil 30 is wound around the teeth part 21 via theconnecting part 12.

The internal circumference part 13 of the insulator 10 has an outer sidesurface in the radial direction opposing to the coil 30. In addition,the inner side surface of the internal circumference part 13 in theradial direction opposes to the bearing housing 90.

Each coupling part 14 of the insulator 10 extends outwards in the radialdirection from the outer circumference part 11 of the insulator 10. Thecoupling parts 14 are coupled to a casing 3 not illustrated in FIGS. 1to 4, and the motor 1 is mounted at the casing 3. Note that the casing 3serves as one example of the external device.

As illustrated in FIG. 1, the insulator 10 includes the two couplingparts 14 opposing to each other in the radial direction. Note that thepresent embodiment describes the insulator 10 including the two couplingparts 14. However, the number of the coupling parts 14 is not limited tothis number. For example, the insulator 10 may include only one couplingpart 14, or may include three or more coupling parts 14.

In the present embodiment, as illustrated in FIG. 1, the motor 1 and thecasing 3 are coupled to each other by the coupling parts 14 provided atthe insulator 10 formed of a resin material, not by an attachment partformed at the housing 70. FIG. 5 is a bottom view illustrating oneexample of the motor according to the first embodiment. As illustratedin FIG. 5, a gap G0 is formed between a tubular part 79 of the housing70 and each coupling part 14 of the insulator 10. This makes it possibleto reduce the size of the housing 70 formed of metal. Thus, it ispossible to reduce the weight of the motor 1. In addition, the couplingparts 14 are formed at the insulator 10 formed of resin having higherelasticity than a metal. Thus, the vibration generated from the motor 1can be reduced due to an internal loss of the resin material when thevibration transfers to the casing 3. In addition, the amplitude of thevibration generated from the motor 1 is reduced due to the internal lossof the resin material. Thus, the vibration can be attenuated in ashorter time. Furthermore, with the insulator 10, the noise generatedfrom the motor 1 is less likely to be transferred. This makes itpossible to achieve noise reduction of the motor 1.

In addition, the fixing part 15 illustrated in FIGS. 1 and 4 is, forexample, a protruding part formed of resin. The first substrate 50 isfixed to the fixing part 15 in the axial direction.

The first conductive member 16 and the second conductive member 17illustrated in FIGS. 1 and 4 are terminal pins used to handle thewinding line that forms the coil 30. In the present embodiment, themotor 1 includes, for example, three first conductive members 16 and onesecond conductive member 17.

For example, winding starts of winding lines of COM, a U phase, a Vphase, and a W phase are wound around the first conductive members 16,and the first conductive members 16 are fixed to the first substrate 50through soldering. This enables the coil 30 and the first substrate 50to be electrically connected.

Furthermore, a winding end of a wiring line of COM is wound around thesecond conductive member 17, and the second conductive member 17includes a resin coating. The second conductive member 17 is fixed tothe first substrate 50 through soldering. In addition, the firstsubstrate 50 and the second substrate 60 are electrically connectedthrough pins (conductive members) 51 a of coupling members 51.Furthermore, the pins 51 a of the plurality of coupling members 51 areelectrically connected to the GND, Vdc, Vcc, and the like, and signalsare transferred from an external device. This enables the coil 30, thefirst substrate 50, and the second substrate 60 to be electricallyconnected to each other.

In the present example, the first substrate 50 and the second substrate60 are disposed so as to oppose to each other in the axial directionwith a gap G1 being provided between the first substrate 50 and thesecond substrate 60, as illustrated in FIGS. 1 and 2. That is, the firstsubstrate 50 and the second substrate 60 are spaced apart from eachother in the axial direction.

As illustrated in FIGS. 1 and 2, the first substrate 50 includes thecoupling members 51, and a first wire line 52. For example, eachcoupling member 51 is a member obtained by covering, with resin, the pin51 a (conductive member) electrically connecting the first substrate 50and the second substrate 60. In the present embodiment, the firstsubstrate 50 includes the five coupling members 51. The first wire line52 is connected to a Hall sensor (not illustrated) provided at the rotor40 side of the first substrate 50. In this manner, the first conductivemember 16, the second conductive member 17, and the coupling members 51including the pins 51 a are used to fix the first substrate 50 and thesecond substrate 60, and to fix the insulator 10 to the first substrate50 and the second substrate 60. This makes it possible to reducestructural elements of the motor 1.

A plurality of electronic components 61 are mounted at the secondsubstrate 60. The electronic components 61 include, for example, acapacitor and an AC-DC converter but are not limited to thesecomponents. In addition, a second wire line 62 configured to supplypower is connected to the second substrate 60.

As illustrated in FIG. 1, the electronic components 61 have a relativelylarge size, as compared with the size of the motor 1. In the presentembodiment, the electronic components 61 are disposed at an upper sidesurface of the second substrate 60 in the axial direction, that is, at asurface disposed at an opposite side in the axial direction from asurface opposing to the first substrate 50 and the insulator 10. Inother words, the electronic components 61 are disposed at a surfaceopposite in the axial direction from the output-side end part 82 of theshaft 80. This makes it possible to reduce the size or the diameter ofthe motor 1.

Furthermore, the sizes, in the radial direction, of the first substrate50 and the second substrate 60 are formed so as to be smaller than thesize, in the radial direction, of the outer circumference part 11 of theinsulator 10. FIG. 6 is an enlarged cross-sectional view illustratingone example of the motor according to the first embodiment. FIG. 6 is anenlarged view of a part indicated by the area F in FIG. 2. Asillustrated in FIG. 6, a gap G2 is formed between the outercircumference part 11 of the insulator 10 and the outer circumferencepart 59 of the first substrate 50 and between the outer circumferencepart 11 of the insulator 10 and the outer circumference part 69 of thesecond substrate 60. The gap G2 forms an annular space C1 surroundingthe outer circumference part 59 of the first substrate 50 and the outercircumference part 69 of the second substrate 60. This makes it possibleto prevent the casing 3 from being brought into contact with the firstsubstrate 50 or the second substrate 60, thereby suppressing transfer ofthe vibration to the casing 3. Note that, an example has been describedwith reference to FIG. 6, and, in this example, the size, in the radialdirection, of the first substrate 50 is substantially the same as thesize, in the radial direction, of the second substrate 60. However, aconfiguration is not limited to this configuration, and it is onlynecessary that, in the radial direction, the outer circumference part 59of the first substrate 50 and the outer circumference part 69 of thesecond substrate 60 be disposed at the inner side than the outercircumference part 11 of the insulator 10. In addition, a gap G4 betweenthe inner surface of the casing 3 and the outer circumference part 59 ofthe first substrate 50 or the outer circumference part 69 of the secondsubstrate 60 may be increased to increase the size of the annular spaceC1. Furthermore, it may be possible to provide a gap G5 between theinner surface of the casing 3 and the outer circumference part 11 of theinsulator 10, provide a space C2 surrounding the outer circumferencepart 11 of the insulator 10 and including the gap G5, and form the spaceC2 largely. With these spaces being provided, air passing through theinside of the motor 1 including the coil 30 more easily flows. Thismakes it possible to suppress an increase in temperature of the motor 1.

In addition, as illustrated in FIG. 6, a gap G3 is formed between thefirst substrate 50 and other members of the motor 1. For example, theouter circumference part 59 of the first substrate 50 and the tubularpart 79 of the metal housing 70 are spaced apart from each other with agap G6 being provided between the outer circumference part 59 and thetubular part 79. This makes it possible to suppress transfer of thevibration of the motor 1 to the first substrate 50 or the secondsubstrate 60.

The bearing housing 90 includes a pair of bearings 91 and 92. Each ofthe bearings 91 and 92 opposes to the shaft 80 in the radial direction.In the present embodiment, an end part 93 of the bearing housing 90 atthe first substrate 50 side in the axial direction oppose s to the yoke42 of the rotor 40 in the axial direction. In addition, the bearinghousing 90 integrally holds the bearing 91 at the lower side in theaxial direction and the bearing 92 at the upper side in the axialdirection. This makes it possible to improve the accuracy of coaxialityof the bearing 91 at the lower side and the bearing 92 at the upperside, thereby achieving the increased service life of the motor 1.

FIG. 7 is a perspective view illustrating one example of the housingaccording to the first embodiment. As illustrated in FIGS. 5 and 7, thehousing 70 includes the tubular part 79 and a bottom surface 71. Thebottom surface 71 constitutes an end surface of the housing 70 at thelower side in the axial direction. An insertion hole 74 to allow theshaft 80 to be inserted is formed in the bottom surface 71. In addition,a plurality of hole parts 72 and a plurality of hole parts 73 are alsoformed in the bottom surface 71. In the present embodiment, the holeparts 72 are formed to have diameters larger than diameters of the holeparts 73. Note that the insertion hole 74 serves as one example of afirst hole part. In addition, the hole parts 72 serve as one example ofa second hole part, and the hole parts 73 serve as one example of athird hole part.

As illustrated in FIG. 5, the hole parts 72 are formed, for example, atpositions opposing to the coil 30 in the axial direction. That is, thehole parts 72 are formed so that air flows inside the motor 1 includingthe coil 30. With the hole parts 72 being formed in the bottom surface71 of the housing 70, it is possible to reduce the weight of the housing70 and to suppress an increase in temperature of the motor 1, forexample, due to self-heating of the coil 30 or heat transferred from thecoil 30 to the stator core 20 or the rotor 40. That is, with the holeparts 72, it is possible to suppress demagnetization of the motor 1 athigh temperatures, deterioration of a resin material of the insulator 10due to heat generation, or the like, and it is also possible to achievethe weight reduction and the increased service life.

Furthermore, the hole parts 73 illustrated in FIG. 7 may be used, forexample, as a positioning hole or screw hole used to attach the housing70 to the insulator 10 or the first substrate 50. In this case, the holeparts 73 may be formed, for example, at positions opposing to the firstsubstrate 50 in the axial direction. This makes it possible to improvean assembling accuracy of the motor 1, and also makes it possible toreduce assembling cost of the motor 1. Note that the housing 70illustrated in FIG. 7 includes the seven hole parts 72 and the five holeparts 73. However, the numbers of the hole parts included in the housing70 are not limited to these numbers.

As described above, the motor 1 according to the present embodimentincludes the rotor 40, the stator 2, the first substrate 50, the secondsubstrate 60, and the electronic components 61 arranged at the secondsubstrate. The stator 2 includes the stator core 20, the insulator 10,and the coil 30 wound around the stator core via the insulator. Theinsulator 10 includes the coupling part 14 coupled to an externaldevice. The first substrate 50 is fixed to the insulator 10. The secondsubstrate 60 is fixed to the first substrate 50, and the first substrate50 and the second substrate 60 are spaced apart from each other in therotation axis direction of the rotor 40. With such a configuration, itis possible to achieve the weight reduction and the noise reduction.

The embodiment according to the present invention has been describedabove. However, the present invention is not limited by the embodimentdescribed above. A configuration obtained by appropriately combining theabove-mentioned constituent elements is also included in the presentinvention. In addition, a skilled person can further derive modificationexamples in an easy manner. Thus, a wide range of aspects of the presentinvention is not limited to the embodiment described above, and may bemodified variously.

REFERENCE SIGNS LIST

1 motor, 2 stator, 3 body, 10 insulator, 11 outer circumference part, 12connecting part, 13 internal circumference part, 14 coupling part, 15fixing part, 16 first conductive member, 17 second conductive member, 18lower insulator, 20 stator core, 21 teeth part, 22 core back, 30 coil,40 rotor, 41 magnet, 42 yoke, 50 first substrate, 51 coupling member, 52first wire line, 59 outer circumference part, 60 second substrate, 61electronic component, 62 second wire line, 69 outer circumference part,70 housing, 71 bottom surface, 72, 73 hole part, 74 insertion hole, 79tubular part, 80 shaft, 90 bearing housing, 91, 92 bearing

1. A motor comprising: a rotor; a stator including a stator core, aninsulator, and a coil wound around the stator core via the insulator; afirst substrate; a second substrate; and an electronic componentarranged at the second substrate, wherein the insulator includes acoupling part coupled to an external device, the first substrate isfixed to the insulator, the second substrate is fixed to the firstsubstrate, and the first substrate and the second substrate are spacedapart in a rotation axis direction of the rotor.
 2. The motor accordingto claim 1, wherein the second substrate is fixed to the first substratevia a coupling member, and the first substrate and the second substrateare fixed to the insulator.
 3. The motor according to claim 1, whereinthe insulator includes an internal circumference part, and an outercircumference part including the coupling part, and the outercircumference part of the insulator includes a fixing part configured tofix the first substrate.
 4. The motor according to claim 1, wherein theinsulator includes a first conductive member configured to electricallyconnect the coil and the first substrate, and the first substrate isfixed to the insulator via the first conductive member.
 5. The motoraccording to claim 1, wherein the coupling member includes a conductivemember configured to electrically connect the coil, the first substrate,and the second substrate.
 6. The motor according to claim 1, wherein, ina radial direction, an outer circumference part of the first substrateand an outer circumference part of the second substrate are disposed ata farther inner side than the outer circumference part of the insulator.7. The motor according to claim 1, comprising: a housing configured toaccommodate a part of the stator, wherein an entire outer circumferencepart of the first substrate and an entire outer circumference part ofthe second substrate are spaced apart from the housing in the rotationaxis direction of the rotor.
 8. The motor according to claim 7, whereinan outer circumference part of the housing is disposed at a fartherinner side than an outer circumference part of the insulator.
 9. Themotor according to claim 7, wherein a first hole part and a plurality ofsecond hole parts having a size differing from the first hole part areformed in a bottom surface of the housing, and a shaft is inserted intothe first hole.
 10. The motor according to claim 9, wherein a third holepart having a size smaller than the second hole parts is further formedin the bottom surface of the housing.
 11. The motor according to claim1, wherein an annular space surrounding an outer circumference part ofthe first substrate and an outer circumference part of the secondsubstrate is formed.